If you have an LG smart TV running WebOS, there's an exploit in the web browser you can use to gain root access and install the homebrew channel. It's literally just going to a website and clicking a couple buttons. From there, you can install a number of different homebrew apps including the aforementioned Jellyfin, as well as ad-free YouTube, RetroArch and of course Doom.
The homebrew channel also lets you run an ssh/telnet server that gives you remote access to the TV's back-end command line and filesystem. I found this functionally extremely useful for allowing the TV to still get online while having it behind a DNS server that blocks access to all of LG's telemetry domains.